Minimally-invasive endoscopic techniques are the standard of care in many specialties. Surgical endoscopy has allowed small incisions to replace large radical surgical approaches, resulting in improved outcomes and reduced operating times. Image guidance, the next technological advancement, provides intra- operative confirmation of surgical anatomy, and also reduces operative time and cost. Image guidance improves surgical performance by precisely mapping surgical anatomy to pre-operative images. Real time overlay of surgical tools onto pre-operative images allows for improved targeting of surgical coordinates. The anatomic constraints of many body cavities, particularly those filled with fat, have limited application of these technologies. Image guidance will facilitate the solution of minimally-invasive flexible endoscopy. Real time display of surgical position is accomplished by measuring and then registering, image space and surgical space. With image guidance we will be able to safely reach remote surgical targets. Traditional image guidance maps rigid tools onto pre-operative images. Many body areas are not well accessed with rigid instruments but could be reached with a flexible endoscope. A tracked flexible endoscope would benefit a wide spectrum of medical and surgical disciplines. An endoscope shows a clear, but myopic, image of the area immediately in front of the camera - it gives no information regarding relative spatial or anatomic relationships. We plan to solve the myopia problem and provide the needed information of where the endoscope is and what it is looking at. This technology will allow for direct treatment of remote targets, best reached with a flexible endoscope. We propose a minimally invasive, image guided endoscopic approach to a surgical target in a fat filled cavity. In order to determine the potential of translating this technology for patient care, we will 1) determine the Target Registration Error and 2) compare performance of image guided endoscopy to non-image guided endoscopy in a surgical model of orbital endoscopy (outcome measures include total time of surgery, time to the optic nerve target, and accuracy of target localization). With the experiments proposed in this study, we will allow for imaged guided flexible endoscopic treatments. PUBLIC HEALTH RELEVANCE: The proposed image-guided flexible endoscope will allow for minimally invasive surgical and medical interventions. Development of this new technology is particularly relevant to the emerging concepts of smaller surgical wounds with less disruption of native anatomy. Access to remote locations will allow for a treatment paradigm shift in many medical disciplines.